Early pre-exposure prophylaxis (PrEP) initiation and continuation among pregnant and postpartum women in antenatal care in Cape Town, South Africa

Introduction Pre-exposure prophylaxis (PrEP) is a safe and effective prevention strategy to reduce women's risk of HIV in pregnancy and postpartum. Effective PrEP protection requires daily PrEP adherence, but little is known about maternal PrEP continuation and factors that influence PrEP use. Methods The PrEP in pregnancy and postpartum (PrEP-PP) study enrolled consenting pregnant, HIV-negative women at first antenatal care (ANC) visit with follow-up through 12 months postpartum. Eligible and consenting women and girls >= 16 years received HIV prevention counselling and were offered PrEP. Interviewers collected socio-demographic and behavioural data from participants at each visit. We analysed the proportion of women who initiated PrEP and the proportion who continued PrEP after 3 months with associated correlates by estimating the prevalence ratio adjusting for a priori confounders. Results Between August 2019 and October 2021, we enrolled 1201 pregnant women (median gestation 21 weeks; age 26 years); 84% of women initiated PrEP at their first ANC visit (n = 1014); 55% were married or cohabiting. Overall, 66% of women on PrEP returned for a repeat prescription at 1 month; 58% returned at 3 months (n = 493 of 844). Almost one-half of women on PrEP reported a side effect at 1 month, mostly nausea/vomiting. Women on PrEP in the first and second trimesters had higher odds of reporting side effects (aOR 2.61; 95% CI 1.17-5.84) versus postpartum women. Women who reported side effects continued with PrEP less than those who did not report side effects (aPR = 0.87; 95% CI 0.77-0.97). Women with >= 1 previous pregnancy (aPR = 0.76; 95% CI 0.57-1.01) or were postpartum (aPR 0.85; 95% CI 0.75-0.97) were less likely to continue PrEP compared to women who were primigravid or pregnant. Women who reported having an HIV+ partner (aPR = 1.45; 95% CI 1.13-1.85) or high HIV risk perception (aPR = 1.20, 95% CI = 1.01-1.41) were more likely to continue on PrEP than those who had HIV-negative partners or low risk perception. Conclusions PrEP initiation and early continuation were high in this setting, compared to other studies in women. Being postpartum and experiencing side effects were associated with lower PrEP continuation, presenting opportunities for counselling on early transient side effects. Interventions for postpartum women on PrEP are needed.